The broad objectives of this study will focus on three areas of neurobiology of the endephalins and endorphins, naturally occurring peptides with narcotic agonist activity. In one series of studies, human lung tumors will be used in order to investigate the biosynthesis of opiate peptides and their relationship to the biosynthesis of ACTH. Studies on the "in situ" labelling of such peptides as well as translation of mRNA extracted from pituitary, brain and tumors will be carried out. In a second series of studies the synaptosomal localization of the opiate peptides will be examined and their ability to be released on electrical stimulation, in order to assess their potential role as neurotransmitters. Thirdly, the effects on release of pituitary hormones of a large number of endephalin analogues will be examined and studies will be carried out using lesioning, radioimmunoassay and immunohistochemical techniques in order to further define the neuroanatomical basis of these effects.